Paleomagnetic and paleoenvironmental implications of magnetofossil occurrences in late Miocene marine sediments from the Guadalquivir Basin, SW Spain

doi:10.3389/fmicb.2014.00071

	Paleomagnetic and paleoenvironmental implications of magnetofossil occurrences in late Miocene marine sediments from the Guadalquivir Basin, SW Spain
	Larrasoana, Juan C.1,2; Liu, Qingsong 3; Hu, Pengxiang 3; Roberts, Andrew P.4; Mata, Pilar 1; Civis, Jorge 1; Sierro, Francisco J.5; Perez-Asensio, Jose N.6
刊名	FRONTIERS IN MICROBIOLOGY
	2014-03-04
卷号	5
关键词	Guadalquivir Basin late Miocene marine sediments rock magnetism magnetotactic bacteria Messinian salinity crisis
ISSN号	1664-302X
DOI	10.3389/fmicb.2014.00071
文献子类	Article
英文摘要	Although recent studies have revealed more widespread occurrences of magnetofossils in pre-Quaternary sediments than have been previously reported, their significance for paleomagnetic and paleoenvironmental studies is not fully understood. We present a paleo- and rock-magnetic study of late Miocene marine sediments recovered from the Guadalquivir Basin (SW Spain). Well-defined paleomagnetic directions provide a robust magnetostratigraphic chronology for the two studied sediment cores. Rock magnetic results indicate the dominance of intact magnetosome chains throughout the studied sediments. These results provide a link between the highest-quality paleomagnetic directions and higher magnetofossil abundances. We interpret that bacterial magnetite formed in the surface sediment mixed layer and that these magnetic particles gave rise to a paleomagnetic signal in the same way as detrital grains. They, therefore, carry a magnetization that is essentially identical to a post-depositional remanent magnetization, which we term a bio-depositional remanent magnetization. Some studied polarity reversals record paleomagnetic directions with an apparent 60-70 kyr recording delay. Magnetofossils in these cases are interpreted to carry a biogeochemical remanent magnetization that is locked in at greater depth in the sediment column. A sharp decrease in magnetofossil abundance toward the middle of the studied boreholes coincides broadly with a major rise in sediment accumulation rates near the onset of the Messinian salinity crisis (MSC), an event caused by interruption of the connection between the Mediterranean Sea and the Atlantic Ocean. This correlation appears to have resulted from dilution of magnetofossils by enhanced terrigenous inputs that were driven, in turn, by sedimentary changes triggered in the basin at the onset of the MSC. Our results highlight the importance of magnetofossils as carriers of high-quality paleomagnetic and paleoenvironmental signals even in dominantly terrigenous sediments.
WOS关键词	MESSINIAN SALINITY CRISIS ; TEMPERATURE MAGNETIC-PROPERTIES ; EQUATORIAL PACIFIC-OCEAN ; ORGANIC-CARBON FLUX ; BIOGENIC MAGNETITE ; MAGNETOTACTIC BACTERIA ; PELAGIC SEDIMENTS ; RELATIVE PALEOINTENSITY ; FERROMAGNETIC-RESONANCE ; REMANENT MAGNETIZATION
WOS研究方向	Microbiology
语种	英语
出版者	FRONTIERS RESEARCH FOUNDATION
WOS记录号	WOS:000332511500001
资助机构	Guadaltyc project (MINECO)(CGL2012-30875) ; Guadaltyc project (MINECO)(CGL2012-30875) ; ARC(DP120103952) ; ARC(DP120103952) ; NSFC(41374073) ; NSFC(41374073) ; Guadaltyc project (MINECO)(CGL2012-30875) ; Guadaltyc project (MINECO)(CGL2012-30875) ; ARC(DP120103952) ; ARC(DP120103952) ; NSFC(41374073) ; NSFC(41374073) ; Guadaltyc project (MINECO)(CGL2012-30875) ; Guadaltyc project (MINECO)(CGL2012-30875) ; ARC(DP120103952) ; ARC(DP120103952) ; NSFC(41374073) ; NSFC(41374073) ; Guadaltyc project (MINECO)(CGL2012-30875) ; Guadaltyc project (MINECO)(CGL2012-30875) ; ARC(DP120103952) ; ARC(DP120103952) ; NSFC(41374073) ; NSFC(41374073)
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/85005]
专题	中国科学院地质与地球物理研究所
通讯作者	Larrasoana, Juan C.
作者单位	1.Inst Geol & Mineiro Espana, Madrid 28003, Spain 2.CSIC, Inst Earth Sci Jaume Almera, Barcelona, Spain 3.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing, Peoples R China 4.Australian Natl Univ, Res Sch Earth Sci, Canberra, ACT, Australia 5.Univ Salamanca, Dept Geol, E-37008 Salamanca, Spain 6.Univ Geneva, Dept Earth Sci, Geneva, Switzerland
推荐引用方式 GB/T 7714	Larrasoana, Juan C.,Liu, Qingsong,Hu, Pengxiang,et al. Paleomagnetic and paleoenvironmental implications of magnetofossil occurrences in late Miocene marine sediments from the Guadalquivir Basin, SW Spain[J]. FRONTIERS IN MICROBIOLOGY,2014,5.
APA	Larrasoana, Juan C..,Liu, Qingsong.,Hu, Pengxiang.,Roberts, Andrew P..,Mata, Pilar.,...&Perez-Asensio, Jose N..(2014).Paleomagnetic and paleoenvironmental implications of magnetofossil occurrences in late Miocene marine sediments from the Guadalquivir Basin, SW Spain.FRONTIERS IN MICROBIOLOGY,5.
MLA	Larrasoana, Juan C.,et al."Paleomagnetic and paleoenvironmental implications of magnetofossil occurrences in late Miocene marine sediments from the Guadalquivir Basin, SW Spain".FRONTIERS IN MICROBIOLOGY 5(2014).